In 221, a year after Cao Jun's elder half-brother Cao Pi ended the Han dynasty and established the state of Cao Wei, Cao Jun was promoted from a marquis to a duke. In 222, he received the title "Prince of Chenliu" (陳留王). Two years later, his princedom was changed from Chenliu (陳留; around present-day Kaifeng, Henan) to Xiangyi County. In 232, during the reign of Cao Pi's son Cao Rui, Cao Jun's princedom was relocated back to Chenliu. Cao Jun died in 259 during the reign of Cao Mao.[3]

Cao Jun was succeeded by his son, Cao Ao (曹澳). The number of taxable households in Cao Ao's princedom increased throughout the reigns of the Wei emperors until it reached 4,700.[4]